Heat relay network system for telecommunication equipment

ABSTRACT

An apparatus, comprising a linecard including a circuit board having a front side connectable to a pluggable optical module and a back side opposite the front side; a heat relay apparatus comprising a heat pipe on the circuit board; a pluggable optical module generating a first amount of heat and being in thermal contact with the heat pipe; and a cooling module including a heat sink in thermal contact with the heat pipe, the cooling module generating a second amount of heat in a range from the first amount of heat to no heat; and wherein heat from the pluggable optical module is transferable through the heat pipe to the cooling module for dispersal from the heat sink.

FIELD OF THE DISCLOSURE

The disclosure generally relates to heat relay network systems fortelecommunication equipment. More particularly, but not by way oflimitation, in one aspect of the present disclosure, the inventiveconcepts relate to heat relay network systems for integrated circuits.In one aspect of the present disclosure, the inventive concepts relateto heat relay network systems for pluggable hot-swappable opticalmultiplexer modules, such as optical modules plugged into a linecard.

BACKGROUND

Telecommunication system circuit packs including pluggable modulehousings are deployed in various communication networks and areconfigured to allow for the hot insertion and hot removal of a varietyof pluggable modules. Components that allow for hot insertion and hotremoval are known as “hot-swappable.” Hot-swappable components can beinserted and/or removed in the field without disassembling the hostsystem, for example, while the host system is in use and/or withoutinterrupting electrical power.

For example, pluggable optical modules used in telecommunication systemsare typically hot swappable. Pluggable optical modules are generallyplugged into a linecard by sliding or otherwise inserting the pluggableoptical module into a housing of the linecard while the linecardcontinues to receive electrical power. The pluggable optical modules maybe positioned in the linecard vertically adjacent to one another and/orlaterally adjacent to one another.

However, it may be difficult to disperse the heat produced by pluggableoptical modules inserted in the linecard. If the heat is not dispersed,the pluggable optical modules and/or the linecard may reach atemperature at which the pluggable optical modules and/or the linecardfail to function properly, or ceases functioning all together.

Therefore, there exists a need for a system to disperse heat fromoptical module systems, including optical modules pluggably engaged withlinecards.

SUMMARY

Systems are disclosed that transfer heat from telecommunicationcomponents downstream in an airflow to components upstream in theairflow. Systems and components are disclosed that manage the dispersalof heat from optical modules pluggably engaged with a linecard. Systemsare disclosed that transfer heat from a pluggable optical module througha heat pipe to a cooling module for heat dispersal.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain embodiments of the inventive concepts will hereafter bedescribed with reference to the accompanying drawings, wherein likereference numerals denote like elements. It should be understood,however, that the accompanying figures illustrate the variousimplementations described herein and are not meant to limit the scope ofthe various technologies described herein.

FIG. 1 is a rear top perspective view of an optical module blind matingheat relay system constructed in accordance with the inventive conceptsdisclosed herein.

FIG. 2 is a front top perspective view of the optical module blindmating heat relay system of FIG. 1.

FIG. 3 is a front bottom perspective view of components of the opticalmodule blind mating heat relay system of FIG. 1.

FIG. 4 is a front top perspective view of a heat relay apparatusconstructed in accordance with the inventive concepts disclosed herein.

FIG. 5 is a front bottom perspective view of a heat relay apparatusconstructed in accordance with the inventive concepts disclosed herein.

FIG. 6 is a side bottom perspective view of a heat relay apparatusconstructed in accordance with the inventive concepts disclosed herein.

FIG. 7 is a perspective view of components of the heat relay apparatusof FIG. 6.

FIG. 8 is a front view of components of the heat relay apparatus of FIG.6.

FIG. 9 is a cross sectional view of the heat relay apparatus of FIG. 6.

FIG. 10 is a cross sectional schematic view of a representative heatpipe constructed in accordance with the inventive concepts disclosedherein

FIG. 11 is a perspective view of a pluggable optical module heat pipeconstructed in accordance with the inventive concepts disclosed herein.

FIG. 12 is a top plan view of a heat relay network system constructed inaccordance with the inventive concepts disclosed herein.

FIG. 13 is a schematic top plan view of another heat relay networksystem constructed in accordance with the inventive concepts disclosedherein.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings.The same reference numbers in different drawings may identify the sameor similar elements.

The mechanisms proposed in this disclosure circumvent the problemsdescribed above. Conventionally, pluggable optical modules used inlinecards have encountered operational problems when overheated. Thepresent disclosure describes systems for dispersal of heat frompluggable optical modules and linecards.

Consistent with an aspect of the present disclosure, An apparatus,comprising a first integrated circuit; a heat sink connected to thefirst integrated circuit; a second integrated circuit on a circuitboard, such that the heat sink and the first integrated circuit beingpositioned upstream in an airflow from the second integrated circuitwhen the circuit board is in use; and a heat pipe having a first portionthermally connected to the first integrated circuit and a second portionthermally connected to the second integrated circuit, such that heat istransferred from the second integrated circuit through the heat pipe fordispersal from the heat sink.

Consistent with an aspect of the present disclosure, a heat relaynetwork system comprises a linecard comprising a circuit board having afront side connectable to a pluggable optical module and a back sideopposite the front side; a heat relay apparatus comprising a heat pipeon the circuit board; a pluggable optical module generating a firstamount of heat and being in thermal contact with the heat pipe; and acooling module including a heat sink in thermal contact with the heatpipe, the cooling module generating a second amount of heat in a rangefrom the first amount of heat to no heat; and wherein heat from thepluggable optical module is transferable through the heat pipe to thecooling module for dispersal from the heat sink.

A method for cooling a telecommunication module, comprising positioninga telecommunication chassis having a heat relay network system in anairflow, the heat relay network system comprising: a linecard comprisinga circuit board having a front side connectable to a pluggable opticalmodule and a back side opposite the front side; a heat relay apparatuscomprising a heat pipe on the circuit board; a pluggable optical modulegenerating a first amount of heat and being in thermal contact with theheat pipe; and a cooling module including a heat sink in thermal contactwith the heat pipe, the cooling module generating a second amount ofheat in a range from the first amount of heat to no heat. The methodfurther comprising transferring heat from the pluggable optical modulethrough the heat pipe to the heat sink of the cooling module; anddispersing heat from the heat sink of the cooling module to the airflow.

Definitions

If used throughout the description and the drawings, the following shortterms have the following meanings unless otherwise stated:

ASIC stands for application-specific integrated circuit. An ASIC is acomputer circuit configured for a specific application.

The term “linecard” as used herein is an optical linecard. Onenonexclusive example of an optical linecard is the Optical TransportNetwork Tributary Module sold by Infinera Corporation of Sunnyvale,Calif.

The term “pluggable optical module” means an insertable and removablecustomer interface to a long-haul optical telecommunication network. Onenonexclusive example of a pluggable optical module is a TributaryInterface Module sold by Infinera Corporation of Sunnyvale, Calif.

DESCRIPTION

Specific embodiments of the inventive concepts disclosed herein will nowbe described in detail with reference to the accompanying drawings.Further, in the following detailed description of embodiments of thepresent disclosure, numerous specific details are set forth in order toprovide a more thorough understanding of the disclosure. However, itwill be apparent to one of ordinary skill in the art that theembodiments disclosed herein may be practiced without these specificdetails. In other instances, well-known features have not been describedin detail to avoid unnecessarily complicating the description.

Unless expressly stated to the contrary, “or” refers to an inclusive orand not to an exclusive or. For example, a condition A or B is satisfiedby anyone of the following: A is true (or present) and B is false (ornot present), A is false (or not present) and B is true (or present),and both A and B are true (or present).

In addition, use of the “a” or “an” are employed to describe elementsand components of the embodiments herein. This is done merely forconvenience and to give a general sense of the inventive concept. Thisdescription should be read to include one or at least one and thesingular also includes the plural unless otherwise stated.

The terminology and phraseology used herein is for descriptive purposesand should not be construed as limiting in scope. Language such as“including,” “comprising,” “having,” “containing,” or “involving,” andvariations thereof, is intended to be broad and encompass the subjectmatter listed thereafter, equivalents, and additional subject matter notrecited or inherently present therein.

As used herein any references to “one embodiment,” “an embodiment,” or“some embodiments” means that a particular element, feature, structure,or characteristic described in connection with the embodiment isincluded in at least one embodiment. The appearances of the phrase “inone embodiment” in various places in the specification may not refer tothe same embodiment.

As used herein, qualifiers like “substantially,” “about,”“approximately,” and combinations and variations thereof, are intendedto include not only the exact amount or value that they qualify, butalso some slight deviations therefrom, which may be due to manufacturingtolerances, measurement error, wear and tear, stresses exerted onvarious parts, and combinations thereof, for example.

The use of the term “at least one” or “one or more” will be understoodto include one as well as any quantity more than one. In addition, theuse of the phrase “at least one of X, V, and Z” will be understood toinclude X alone, V alone, and Z alone, as well as any combination of X,V, and Z.

The use of ordinal number terminology (i.e., “first”, “second”, “third”,“fourth”, etc.) is solely for the purpose of differentiating between twoor more items and, unless explicitly stated otherwise, is not meant toimply any sequence or order or importance to one item over another orany order of addition.

It is noted that the terms “top,” “bottom,” “side,” “front,” and “rear,”as used herein, are for ease of description, and are not intended tolimit the orientation of components or the scope of the invention. Oneof skill in the art will readily appreciate that the physicalorientation of an optical-electrical device, such as an optical module,may be positioned in any orientation

Typically, the use of heat pipe assemblies with hot-swappablecomponents, such as pluggable optical modules, has been limited sinceheat pipes typically are soldered together as one inseparable component.Additionally, space for heat dispersal components is limited onhot-swappable components due to requirements for connecting thehot-swappable components and specified spacing in the housings of thereceiving components (such as linecards).

Fiber optic modules are typically mounted to a chassis or housing whichis then mounted inside an equipment rack or cabinet. The linecards andchasses into which the hot-swappable modules are inserted have potentialheat dispersal areas. To utilize the heat dispersal areas of thelinecard and/or chasses, systems are needed that transfer heat from thehot-swappable module.

Additionally, conventional heat pipe assemblies encounter problems withtolerance stack ups that cause mounting problems for the heat pipeassemblies. Current heat pipe designs require precise assembly andmounting locations. If a heat pipe assembly is too long, too short, tootall, or non-parallel with the connection, a connected cold plate maynot sit properly.

Referring now to the drawings, and in particular to FIGS. 1-3, showntherein and designated by reference numeral 10 is an optical moduleblind mating heat relay system constructed in accordance with thepresent invention. In general, the optical module blind mating heatrelay system 10 comprises a linecard 12, a heat relay apparatus 14connected to the linecard 12, at least one pluggable optical module 16removably engaged with the linecard 12, and at least one pluggableoptical module heat pipe 18 contacting the pluggable optical module 16and removably engaged with the heat relay apparatus 14. In the exampleshown, the optical module blind mating heat relay system 10 includes sixpluggable optical modules 16 and pluggable optical module heat pipes 18engaged with the heat relay apparatus 14.

The linecard 12 has a circuit board 30 having a front side 32 and a backside 34 opposite the front side 32. The circuit board 30 may be amidplane circuit board 30. The front side 32 of the midplane circuitboard 30 is connectable to the pluggable optical module 16. The backside 34 of the midplane circuit board 30 is connectable to externaldevices, such as other circuit boards, circuitry, electrical connectors,other modules, and so on, as is well known by those having ordinaryskill in the art. The linecard 12 may also comprise a support base 36and card guides 38 removably attached to the support base 36. The cardguides 38 and support base 36 may guide and support the pluggableoptical module 16 generally toward and away from the midplane circuitboard 30. The linecard 12 may be insertable in a telecommunicationequipment chassis (not shown). The midplane circuit board 30 may connectthe pluggable optical modules 16 to a main circuit board (not shown) ofthe linecard 12.

As illustrated in FIGS. 4-6, the heat relay apparatus 14 comprises atleast one heat relay receiver assembly 40, a midplane heat pipe 42, anda radiator 46. Six heat relay receiver assemblies 40 are depicted by wayof example in FIG. 4. The heat relay receiver assemblies 40 are inthermal contact with the midplane heat pipe 42, which is in thermalcontact with the radiator 46. The heat relay receiver assembly 40 andthe midplane heat pipe 42 may be positioned on the front side 32 of themidplane circuit board 30. The radiator 46 may be positioned on the backside 34 of the midplane circuit board 30. The heat relay receiverassembly 40, midplane heat pipe 42, and radiator 46 may be adjacent toor touching the midplane circuit board 30.

In one aspect of the present disclosure, the heat relay apparatus 14further comprises a heat relay frame 50 attached to the front side 32 ofthe midplane circuit board 30. The heat relay receiver assembly 40 andthe midplane heat pipe 42 may be attached to the heat relay frame 50.

The exemplary optical module blind mating heat relay system 10 shown inthe figures has six heat relay receiver assemblies 40 for explanatorypurposes. However, it will be understood that the optical module blindmating heat relay system 10 may have one, two, three, four, five, six,or more of the heat relay receiver assemblies 40.

As illustrated in FIGS. 7-9, the heat relay receiver assembly 40 mayhave a receiver housing 60 having a slot 62. The receiver housing 60 maybe made of plastic, metal, or other material with heat transferabilities capable of transferring heat from the pluggable optical moduleheat pipe 18 to the midplane heat pipe 42. The receiver housing 60 maybe die cast. The receiver housing 60 may be made of a combination ofmaterials. The slot 62 of the receiver housing 60 is shaped to receiveand be removably coupled to the pluggable optical module heat pipe 18.The slot 62 of the receiver housing 60 may be shaped to removably retainthe pluggable optical module heat pipe 18 in place in the receiverhousing 60.

As shown in FIGS. 6 and 7, the heat relay receiver assembly 40 mayfurther comprise a contact slug 64 in thermal contact with the receiverhousing 60. The contact slug 64 may be connected to the receiver housing60 or part of the receiver housing 60. The contact slug 64 is also inthermal contact with the midplane heat pipe 42. The contact slug 64 maybe positioned in, or partially in, the receiver housing 60.

In one aspect of the present disclosure, the contact slug 64 is inthermal contact with the pluggable optical module heat pipe 18 and themidplane heat pipe 42.

In one aspect of the present disclosure, the contact slug 64 isconnected to the midplane heat pipe 42, such as by soldering the contactslug 64 to the midplane heat pipe 42.

The contact slug 64 may be made of materials having thermal conductivitysufficient to conduct heat from the system. In one aspect of the presentdisclosure, the contact slug 64 may be made of thermally conductivematerial sufficient to transfer heat produced by the pluggable opticalmodule 16. Non-exclusive examples of thermally conductive materialinclude copper and aluminum. In one aspect of the present disclosure,the contact slug 64 is made of aluminum 6063 having a thermalconductivity of approximately 210 W/(m*K). In one aspect of the presentdisclosure, the contact slug 64 is made of copper having a thermalconductivity of approximately 380 W/(m*K).

In one aspect of the present disclosure, the contact slug 64 is made ofcopper with nickel plating. Nickel plating may improve heat transferbetween surfaces as the nickel plating may increase the flatness of thesurfaces, thereby decreasing air gaps between the surfaces and loweringthermal resistance.

In one aspect of the present disclosure, the contact slug 64 has asubstantially rectangular shape having a first planar surface configuredto matingly engage with the pluggable optical module heat pipe 18. Inone aspect of the present disclosure, the contact slug 64 has a secondplanar surface configured to contact the midplane heat pipe 42. In oneaspect of the present disclosure, the contact slug 64 has a lengthbetween approximately one and one-third inch and two inches, and a widthbetween one-half inch and one inch.

In one aspect of the present disclosure, the contact slug 64 has anangled leading edge, for ease of insertion of the pluggable opticalmodule heat pipe 18 into the receiver housing 60.

In one aspect of the present disclosure, the heat relay receiverassembly 40 may further comprise a clip 66 located inside the slot 62 ofthe receiver housing 60. The contact slug 64 may be in thermal contactwith the clip 66 in the receiver housing 60. The clip 66 may be shapedto receive and/or removably retain the pluggable optical module heatpipe 18. The clip 66 may aid in reducing wear to the receiver housing 60and/or the pluggable optical module heat pipe 18, allowing for a greaternumber of insertions and removals of the pluggable optical module heatpipe 18. The clip 66 may be made of, or lined with, a material having alow coefficient of friction for ease of insertion and removal of thepluggable optical module heat pipe 18. Non-exclusive examples of lowfriction materials include metal alloys containing copper (for example,bronze), metal alloys plated with nickel, and some plastics (forexample, polytetrafluorethylene). Electroless nickel plating may be usedon copper alloys to produce a low friction material, such as electrolessnickel plating that has a dynamic friction coefficient against itself of0.43.

In one aspect of the present disclosure, the first planar surface of thecontact slug 64 is configured to contact the clip 66.

As shown in FIG. 9, in one aspect of the present disclosure, the heatrelay receiver assembly 40 may further comprise a leaf spring 68extending into the slot 62 of the receiver housing 60. The leaf spring68 may oppose the contact slug 64 and thereby bias the pluggable opticalmodule heat pipe 18 toward the contact slug 64. The leaf spring 68 mayhave any suitable shape such that the pluggable optical module heat pipe18 is biased toward the contact slug 64. In FIG. 9, the leaf spring 68is shown having one radial contact point with the pluggable opticalmodule heat pipe 18, however, it will be understood that the leaf spring68 may have multiple contact points, or be of other shapes, as is wellknown by one having ordinary skill in the field of mechanical leafsprings 68.

It will be understood that other components may be used with or insteadof the leaf spring 68, such that the pluggable optical module heat pipe18 is biased toward the contact slug 64. Non-exclusive examples includeone or more spring and one or more compressible material. Additionally,it will be understood that the receiver housing 60 may be shaped toremovably engage the pluggable optical module heat pipe 18 in a biasedposition with the contact slug 64.

In one aspect of the present disclosure, the heat relay receiverassembly 40 may further comprise a compressible thermal gap filler 72between the pluggable optical module heat pipe 18 and the contact slug64. In one aspect of the present disclosure, the heat relay receiverassembly 40 may further comprise the compressible thermal gap filler 72between the pluggable optical module heat pipe 18 and the clip 66.

The compressible thermal gap filler 72 may be in the form of a pad, agel, a spring, or any other compressible material with sufficientthermal transfer properties to transfer heat from the pluggable opticalmodule heat pipe 18 to the clip 66 and/or contact slug 64. Thecompressible thermal gap filler 72 has higher heat conductivity than airand helps to fill any gaps between components, so as to increase thermalconductivity and lower thermal resistance between components. Thethermal compressible gap filler may have a thermal conductivity ofbetween approximately 1.5 W/(m*K) and 5 W/(m*K). The compressiblethermal gap filler 72 may be a commercially available product, such asBergquist thermal material products provided by Henkel ElectronicsMaterials, LLC, of Chanhassen, Minn., or compressible thermal gapfillers 72 provided by Laird, of Earth City, Mo.

In one aspect of the present disclosure, the compressible thermal gapfiller 72 may have a thermal conductivity of approximately 1.8 W/m*K.

Turning now to FIGS. 4-6, the exemplary optical module blind mating heatrelay system 10 shown in the figures has two midplane heat pipes 42 forexplanatory purposes. However, it will be understood that the opticalmodule blind mating heat relay system 10 may have one, two, three, four,five, six, or more of the midplane heat pipes 42. The midplane heatpipes 42 may be thermally connected to more than one heat relay receiverassembly 40.

In one aspect of the present disclosure, as shown in FIGS. 4-6, theoptical module blind mating heat relay system 10 comprises a firstmidplane heat pipe 42 thermally connected to a first heat relay receiverassembly 40 as well as to a second heat relay receiver assembly 40 and athird heat relay receiver assembly 40. The optical module blind matingheat relay system 10 further comprises a second midplane heat pipe 42thermally connected to a fourth heat relay receiver assembly 40 as wellas to a fifth heat relay receiver assembly 40 and a sixth heat relayreceiver assembly 40.

As shown in FIG. 9, the midplane heat pipe 42 may have a first portion80 having a substantially rectangular cross-sectional shape having afirst side 82 and a second side 84. The first side 82 may be in thermalcontact with the heat relay receiver assembly 40. At least part of thefirst portion 80 of the midplane heat pipe 42 in thermal contact withthe heat relay receiver assembly 40 is shaped to matingly engage theheat relay receiver assembly 40. For example, the first side 82 of thefirst portion 80 may be substantially flat, as heat transfer is improvedbetween components with greater contact between the components.

As shown in FIGS. 4-6, the midplane heat pipe 42 may have a secondportion 86 in thermal contact with the radiator 46. In one aspect of thepresent disclosure, the second portion 86 of the midplane heat pipe 12has a substantially rectangular cross-sectional shape. At least part ofthe second portion 86 of the midplane heat pipe 42 is shaped to matinglyengage the radiator 46. For example, the part of the second portion 86in thermal contact with the radiator 46 may be substantially flat, asheat transfer is improved between components with greater contactbetween the components.

In one aspect of the present disclosure, the midplane heat pipe 42 maybe an approximately eight millimeter diameter cylindrical heat pipeflattened in portions to an approximately four millimeter thick heatpipe. In one aspect of the present disclosure, the midplane heat pipe 42may be an approximately nine millimeter diameter cylindrical heat pipeflattened in portions to an approximately four millimeter thick heatpipe. Of course, it will be understood that the midplane heat pipe 42may be larger or smaller. The size of the midplane heat pipe 42 maydepend at least in part on available space on the linecard 12.

As shown in FIG. 5, in one aspect of the present disclosure, someportions of the midplane heat pipe 42 may have a substantiallyrectangular cross-sectional shape while other portions of the midplaneheat pipe 42 may have a cylindrical shape.

In one aspect of the present disclosure, as shown in FIG. 4, themidplane heat pipe 42 may have a substantially rectangularcross-sectional shape along substantially the entire length of themidplane heat pipe 42.

The midplane heat pipe 42 may be comprised of thermally conductivematerial or combinations of materials. In one aspect of the presentdisclosure, the midplane heat pipe 42 may be a fluid-wick type heat pipe90. As illustrated in the schematic of FIG. 10, in one aspect of thepresent disclosure, the fluid-wick type heat pipe 90 may comprise anouter wall 100 made of a highly thermally conductive material(non-exclusive examples of which include copper or aluminum) surroundinga capillary wicking material 102 and a fluid 104. Non-exclusive examplesof such fluid 104 include water, acetone, methanol, and the like. Whenthe fluid 104 in the midplane heat pipe 42 absorbs heat, the fluid 104evaporates to vapor 106. The vapor 106 moves along the interior of thefluid-wick type heat pipe 90 to a lower temperature portion of thefluid-wick type heat pipe 90, such as the portion of the fluid-wick typeheat pipe 90 in thermal contact with the radiator 46. There the vapor106 condenses back to fluid 104, releasing thermal energy, and the fluid104 is absorbed by the wicking material 102. The fluid 104 then flowsthrough the wicking material 102 back to the portion of the fluid-wicktype heat pipe 90 that is a higher temperature, such as the firstportion of the fluid-wick type heat pipe 90.

Turning now to the radiator 46, as illustrated in FIGS. 1 and 4, theradiator 46 may comprise fins 110. The fins 110 may act to disperse heatinto the surrounding air. The radiator 46 may be sized to disperse theheat from the pluggable optical modules 16. The radiator 46 may be sizedto correspond to the size of the midplane circuit board 30, such thatelectrical connections may still be made to the midplane circuit board30.

In one aspect of the present disclosure, the radiator 46 has a lengthsubstantially equal to the length of the back side 34 of the midplanecircuit board 30.

In one aspect of the present disclosure, the radiator 46 has a length ofapproximately 19 inches to 20 inches. In one aspect of the presentdisclosure, the fins 110 of the radiator 46 have a height ofapproximately three-quarters of an inch and a length betweenapproximately three-eighths of an inch and seven-sixteenths of an inch.Of course, it will be understood that the radiator 46 and the fins 110may be of any size sufficient to disperse the heat from the pluggableoptical modules 16.

In one aspect of the present disclosure, the heat relay apparatus 14 maycomprise additional components for heat transfer from the midplane heatpipe 42 and the radiator 46. In one aspect of the present disclosure,the heat relay apparatus 14 may comprise a first conductor 120 inthermal contact with the midplane heat pipe 42 and the radiator 46, thustransferring heat from the midplane heat pipe 42 to the radiator 46. Inone aspect of the present disclosure, the heat relay apparatus 14 maycomprise a second conductor 122 in thermal contact with the midplaneheat pipe 42 and the radiator 46, thus transferring heat from themidplane heat pipe 42 to the radiator 46. In applications in which themidplane heat pipe 42 is aligned substantially vertically, the firstconductor 120 may be aligned vertically over the second conductor 122.

In one aspect of the present disclosure, the second portion 86 of themidplane heat pipe 42 has a first end portion 124 and a second endportion 126. The first end portion 124 is in thermal contact with thefirst conductor 120 and the second end portion 126 is in thermal contactwith the second conductor 122.

As illustrated in FIG. 6, in one aspect of the present disclosure, theheat relay apparatus 14 may comprise a radiator heat pipe 130 locatedbetween the first and second conductors 120, 122 and the radiator 46. Inone aspect of the present disclosure, the heat relay apparatus 14 maycomprise two radiator heat pipes 130 located between the first andsecond conductors 120, 122 and the radiator 46. The radiator heatpipe(s) 130 may extend along a length of and disperse heat along theradiator 46. The radiator heat pipe(s) 130 may have a portion having arectangular cross-sectional shape. In one aspect of the presentdisclosure, the radiator heat pipe(s) may be fluid-wick type heatpipe(s) 90.

Returning now to FIGS. 1 and 2, as previously discussed, the pluggableoptical modules 16 are removably engaged with the linecard 12. Thepluggable optical modules 16 may be inserted and removed from thelinecard 12 utilizing the card guides 38. The exemplary optical moduleblind mating heat relay system 10 shown in the figures has six pluggableoptical modules 16 for explanatory purposes. However, it will beunderstood that the optical module blind mating heat relay system 10 mayhave one, two, three, four, five, six, or more of the pluggable opticalmodules 16. The pluggable optical modules 16 are removably engaged withthe linecard 12 and are hot-swappable. The number and purpose of thepluggable optical modules 16 may vary depending on the needs of thetelecommunication system.

In one aspect of the present disclosure, the respective pluggableoptical modules 16 may be connected to a heat sink 140 located on thepluggable optical module 16. In one aspect of the present disclosure,the pluggable optical module 16 may have multiple heat sinks 140 locatedon the pluggable optical module 16 (not shown).

Turning now to the pluggable optical module heat pipe 18 illustrated inFIGS. 3 and 11, the pluggable optical module heat pipe 18 has apluggable optical module portion 150 connected to and in thermal contactwith the pluggable optical module 16. The pluggable optical moduleportion 150 can be soldered to the pluggable optical module 16, forexample. The pluggable optical module heat pipe 18 has a plug portion152 removably positioned within the slot 62 of the receiver housing 60of the heat relay receiver assembly 40. The plug portion 152 is inthermal contact with the contact slug 64 so that heat is transferred outof the pluggable optical module heat pipe 18. The plug portion 152 ofthe pluggable optical module heat pipe 18 is removable from the receiverhousing 60 of the heat relay receiver assembly 40 while the linecard 12is receiving electrical power.

The exemplary optical module blind mating heat relay system 10 shown inthe figures has six pluggable optical module heat pipes 18 forexplanatory purposes. However, it will be understood that the opticalmodule blind mating heat relay system 10 may have one, two, three, four,five, six, or more of the pluggable optical module heat pipes 18. Thepluggable optical module heat pipes 18 are removably engaged with thelinecard 12 such that the pluggable optical modules 16 arehot-swappable.

In one aspect of the present disclosure, the pluggable optical moduleportion 150 and/or the plug portion 152 of the pluggable optical moduleheat pipe 18 may have a substantially rectangular cross-sectional shape.The plug portion 152 may have a substantially flat surface in thermalcontact with the contact slug 64. The pluggable optical module portion150 may have a substantially flat surface in thermal contact with thepluggable optical module 16 located on the pluggable optical module 16.

In one aspect of the present disclosure, the pluggable optical moduleportion 150 is in thermal contact with the heat sink 140 located on thepluggable optical module 16. The pluggable optical module portion 150may have a substantially flat surface in thermal contact with the heatsink 140 of the pluggable optical module 16.

In one aspect of the present disclosure, the pluggable optical moduleportion 150 and/or the plug portion 152 of the pluggable optical moduleheat pipe 18 may have a thickness of approximately three millimeters. Inone aspect of the present disclosure, the pluggable optical moduleportion 150 and/or the plug portion 152 of the pluggable optical moduleheat pipe 18 may have a width of approximately twelve millimeters.

In one aspect of the present disclosure, the pluggable optical moduleportion 150 and the plug portion 152 of the pluggable optical moduleheat pipe 18 may be horizontally offset from one another when thelinecard 12 is in a vertical position.

The pluggable optical module heat pipe 18 may be comprised of thermallyconductive material or combinations of materials. The pluggable opticalmodule heat pipe 18 may be a fluid-wick type heat pipe 90, as previouslydescribed in conjunction with FIG. 10.

As illustrated in FIG. 11, in one aspect of the present disclosure, theoptical module blind mating heat relay system 10 further comprises athermally conductive connector 160, such as a plate, connected to thepluggable optical module portion 150 of the pluggable optical moduleheat pipe 18. The connector 160 is in thermal contact with the contactslug 64 of the heat relay receiver assembly 40. The connector 160 mayhave a substantially flat side 162 in thermal contact with the contactslug 64. In one aspect of the present disclosure, the flat side 162 ofthe connector 160 is in direct contact with the contact slug 64.

An example of use of the exemplary optical module blind mating heatrelay system 10 of FIGS. 1-9 will be described. However, it will beunderstood that elements of any aspects described in the disclosure inany number or combination may be used such that the optical module blindmating heat relay system 10 may disperse heat from the pluggable opticalmodules 16 engaged in the linecard 12.

In use, the linecard 12 may be connected to a larger telecommunicationsystem and actively powered. An operator may insert a pluggable opticalmodule 16 in the linecard 12 such that the pluggable optical module 16is guided along the card guides 38. When the pluggable optical module 16is inserted, the plug portion 152 of the pluggable optical module heatpipe 18 is aligned with and inserted in the slot 62 of the receiverhousing 60 of the heat relay receiver assembly 40, such that the leafspring 68 of the heat relay receiver assembly 40 engages the plugportion 152 of the pluggable optical module heat pipe 18.

The clip 66 of the heat relay apparatus 14 decreases the force needed toinsert the plug portion 152 of the pluggable optical module heat pipe 18into the clip 66 in the slot 62, as well as decreasing frictional wearof the plug portion 152.

Once inserted into the slot 62, the leaf spring 68 engages and biasesthe plug portion 152 of the pluggable optical module heat pipe 18against the thermal gap filler 72 toward the contact slug 64. The leafspring 68 assists in retaining the pluggable optical module heat pipe 18in the receiver housing 60 of the heat relay receiver assembly 40.

As the pluggable optical module 16 is operated, heat is generated by thepluggable optical module 16. The heat is transferred from the pluggableoptical module 16 into the pluggable optical module portion 150 of thepluggable optical module heat pipe 18. The heat is then transferred bythe pluggable optical module heat pipe 18 through the plug portion 152of the pluggable optical module heat pipe 18 into the heat relayreceiver assembly 40. The heat is conducted through the thermal gapfiller 72 to the clip 66 to the contact slug 64. The contact slug 64transfers the heat into the midplane heat pipe 42.

The midplane heat pipe 42 transfers the heat to the first conductor 120and/or the second conductor 122. The first conductor 120 and/or secondconductor 122 transfer the heat to the radiator 46 on the back side 34of the midplane circuit board 30. The first conductor 120 and/or secondconductor 122 may transfer the heat to the radiator 46 at least in partthrough the radiator heat pipes 130.

Airflow around the fins 110 of the radiator 46 disperses the heat out ofthe radiator 46 and away from the pluggable optical modules 16.

The optical module blind mating heat relay system 10 thereby dispersesheat from the pluggable optical modules 16 to the heat relay apparatus14 on the linecard 12 and then away from the linecard 12, thusdecreasing the temperature of the pluggable optical modules 16 and thelinecard 12.

When an operator determines that the pluggable optical module 16 shouldbe removed or replaced, for example, due to system needs, the operatorslides the pluggable optical module 16 out of the linecard 12 whichcauses the plug portion 152 of the pluggable optical module heat pipe 18to disengage from clip 66 in the slot 62 of the receiver housing 60 ofthe heat relay receiver assembly 40. The pluggable optical module 16, oranother pluggable optical module 16, may be reinserted in a similarmanner as described above.

In one aspect of the present disclosure, FIG. 12 illustrates a heatrelay network system 200 for telecommunication equipment constructed inaccordance with the inventive concepts disclosed herein. The heat relaynetwork system 200 may be substantially similar to the optical moduleblind mating heat relay system 10 except as described herein below. Theheat relay network system 200 comprises the linecard 12, the pluggableoptical module 16, the pluggable optical module heat pipe 18, a heatrelay apparatus 14 a, and a cooling module 202.

In one aspect of the present disclosure, the pluggable optical module 16may be connected to the heat sink 140.

In one aspect of the present disclosure, the heat relay network system200 comprises the radiator 46. In another aspect of the presentdisclosure, the heat relay network system does not include the radiator46.

As previously described, the linecard 12 comprises a midplane circuitboard 30. In the heat relay network system 200, the heat relay apparatus14 a is substantially similar to the heat relay apparatus 14, except asdescribed herein below. The heat relay apparatus 14 a comprises themidplane heat pipe 42 on the midplane circuit board 30.

The pluggable optical module 16 is in thermal contact with the midplaneheat pipe 42 through the pluggable optical module heat pipe 18. Thepluggable optical module 16 generates a first amount of heat when inuse.

The cooling module 202 has, and/or is connected to, a heat sink 204 inthermal contact with the midplane heat pipe 42. The cooling module 202generates a second amount of heat in a range from the first amount ofheat to no heat.

In one aspect of the present disclosure, the cooling module 202 may be apluggable optical module 16. In one aspect of the present disclosure,the cooling module 202 may have one or more components of the pluggableoptical module 16. In one aspect of the present disclosure, the coolingmodule 202 may be an inactive, deactivated, inert, and/or unpoweredpluggable optical module 16. In one aspect of the present disclosure,the cooling module 202 may be a pluggable optical module 16 having oneor more inactive and/or inactivated components.

In use, the heat from the pluggable optical module 16 is transferablethrough the midplane heat pipe 42 to the cooling module 202 fordispersal from the heat sink 204.

In one aspect of the present disclosure, the heat relay apparatus 14 amay have the first heat relay receiver assembly 40 comprising the firstreceiver housing 60 having the slot 62 and in thermal contact with themidplane heat pipe 42. The heat relay apparatus 14 a may also have thesecond heat relay receiver assembly 40 comprising the second receiverhousing 60 having the slot 62 and in thermal contact with the midplaneheat pipe 42.

In one aspect of the present disclosure, the heat relay network system200 may have the pluggable optical module heat pipe 18 having thepluggable optical module portion 150 contacting the pluggable opticalmodule 16 and the plug portion 152 removably positioned within the slot62 of, and in thermal contact with, the first receiver housing 60 of thefirst heat relay receiver assembly 40.

In one aspect of the present disclosure, the heat relay network system200 may have a cooling module heat pipe 206 having a heat sink portion208 in thermal contact with the heat sink 204 and a plug portion 210removably positioned within the slot 62 of, and in thermal contact with,the second receiver housing 60 of the second heat relay receiverassembly 40.

In one aspect of the present disclosure, the heat relay apparatus 14 amay have a first one of the contact slug 64 in between and in thermalcontact with the first receiver housing 60 and the midplane heat pipe42. In one aspect of the present disclosure, the heat relay apparatus 14a may have a second one of the contact slug 64 in between and in thermalcontact with the second receiver housing 60 and the midplane heat pipe42.

In one aspect of the present disclosure, the cooling module 202 isremovable from, and/or engageable with, the linecard 12 while thelinecard 12 is receiving electrical power. In one aspect of the presentdisclosure, the cooling module heat pipe 206 is removable from, and/orengageable with, the second heat relay receiver assembly 40 while thelinecard 12 is receiving electrical power.

In one aspect of the present disclosure, the heat relay network system200 may have more than one of the heat pipes 42. In one aspect of thepresent disclosure, the heat pipe(s) 42 may be the fluid-wick type heatpipe 90, as previously described in relation to FIG. 10.

Although FIG. 12 shows two pluggable optical modules 16 and one coolingmodule 202, it will be understood that the heat relay network system 200may have one, two, three, or more of the pluggable optical module(s) 16and one, two, three, or more of the cooling module(s) 202.

In use, heat from the pluggable optical module 16 is transferablethrough the pluggable optical module heat pipe 18, the midplane heatpipe 42, and the cooling module heat pipe 206 to the cooling module 202for dispersal from the heat sink 204 of the cooling module 202.

In use, an operator may position the heat relay network system 200 in atelecommunication chassis (not shown) having an airflow 220 into thetelecommunication chassis and across the heat relay network system 200.The operator may position the heat relay network system 200 such thatthe cooling module 202 is upstream in the airflow 220 from the pluggableoptical module 16. The term “upstream” as used herein, refers to aposition that encounters the airflow before components positioned“downstream” encounter the airflow 220.

Thus, as the pluggable optical module 16 produces heat, the heat istransferred to the midplane heat pipe 42 and then to the heat sink 204of the cooling module 202. The heat is dispersed from the heat sink 204of the cooling module 202 to the airflow 220.

FIG. 13 illustrates another heat relay network system 200 a fortelecommunication equipment substantially similar to the heat relaynetwork system 200 except as described herein below. The heat relaynetwork system 200 a has a first integrated circuit 250 on a circuitboard 254; a second integrated circuit 256 having, and/or connected to,a heat sink 258 and positionable upstream in the airflow 220 from thefirst integrated circuit 250 when the circuit board 254 is in use; and aheat pipe 42 a having a first portion 260 thermally connected to thefirst integrated circuit 250 and a second portion 262 thermallyconnected to the second integrated circuit 256, such that heat istransferred from the first integrated circuit 250 for dispersal from theheat sink 258 of the second integrated circuit 256.

In one aspect of the present disclosure, the heat sink 258 is a firstheat sink, and the first integrated circuit 250 may have, and/or beconnected to, a second heat sink 252 and the first portion 260 of theheat pipe 42 a may be thermally connected to the second heat sink 252.

Although FIG. 13 shows three integrated circuits 250, 256, 264, it willbe understood that the heat relay network system 200 a may have anynumber of integrated circuits in thermal contact with the heat pipe 42a. Further, it will be understood that the first integrated circuit 250and the second integrated circuit 256 may be on the circuit board 254 ormay be positioned on separate circuit boards.

In one aspect of the present disclosure, the first integrated circuit250 is an application-specific integrated circuit. In one aspect of thepresent disclosure, the second integrated circuit 256 is anapplication-specific integrated circuit.

In one aspect of the present disclosure, the heat relay network system200 a may have more than one of the heat pipes 42 a. In one aspect ofthe present disclosure, the heat pipe(s) 42 a may be the fluid-wick typeheat pipe 90, as previously described in relation to FIG. 10.

In use, an operator may position in a telecommunication chassis (notshown) having the heat relay network system 200 a in an airflow 220. Theoperator may position the chassis such that the heat relay networksystem 200 a is positioned such that the second integrated circuit 256is upstream in the airflow 220 from the first integrated circuit 250. Insuch a position, the first integrated circuit 250 may have less heatdispersal at the location of the first integrated circuit 250 to theairflow 220 due to lesser amounts of airflow 220 reaching the firstintegrated circuit 250 than when the airflow 220 enters the chassisand/or due to the airflow 220 having a higher temperature when theairflow 220 reaches the first integrated circuit 250 than when theairflow 220 enters the chassis.

When the first integrated circuit 250 is in use, the heat generated bythe first integrated circuit 250 is transferred through the heat pipe 42a to the heat sink 258 of second integrated circuit 256. The heat isthen dispersed to the airflow 220 from the heat sink 258 of secondintegrated circuit 256 into the airflow 220.

The first integrated circuit 250 and the second integrated circuit 256may both be producing heat when in use. The second integrated circuit256, upstream in the airflow 220 from the first integrated circuit 250,is at a higher temperature than the second integrated circuit 256 wouldbe if the second integrated circuit 256 were not connected to the firstintegrated circuit 250, but at a lower temperature than the firstintegrated circuit 250. Thus, heat is transferred to the secondintegrated circuit 256 at a level sufficient to reduce the temperatureof the pre-heated first integrated circuit 250 located downstream in theairflow 220. Therefore, the heat is distributed more evenly across thefirst integrated circuit 250 and the second integrated circuit 256.

In one aspect of the present disclosure, the heat transfer is such thatthe first integrated circuit 250 and the second integrated circuit 256are at temperatures within predetermined temperature safety margins forproper functioning of the first integrated circuit 250 and the secondintegrated circuit 256.

CONCLUSION

As power and heat requirements for pluggable optical modules 16 haveincreased, heat dispersal systems are needed to prevent drops inperformance and failures of the pluggable optical modules 16. Inaccordance with the present disclosure, heat is dispersed from thepluggable optical modules 16.

The foregoing description provides illustration and description, but isnot intended to be exhaustive or to limit the inventive concepts to theprecise form disclosed. Modifications and variations are possible inlight of the above teachings or may be acquired from practice of themethodologies set forth in the present disclosure.

Further, while implementations have been described in the context ofoptical telecommunication systems, this need not be the case. Theseimplementations may apply to supporting any type of electronic and/oroptical equipment within a stacked housing, such as computer servers,power supplies, communication equipment or the like.

Even though particular combinations of features are recited in theclaims and/or disclosed in the specification, these combinations are notintended to limit the disclosure. In fact, many of these features may becombined in ways not specifically recited in the claims and/or disclosedin the specification. Although each dependent claim listed below maydirectly depend on only one other claim, the disclosure includes eachdependent claim in combination with every other claim in the claim set.

No element, act, or instruction used in the present application shouldbe construed as critical or essential to the invention unless explicitlydescribed as such outside of the preferred embodiment. Further, thephrase “based on” is intended to mean “based, at least in part, on”unless explicitly stated otherwise.

What is claimed is:
 1. An apparatus, comprising: a linecard comprising acircuit board having a front side connectable to a pluggable opticalmodule and a back side opposite the front side; a heat relay apparatuscomprising a heat pipe on the circuit board; the pluggable opticalmodule generating a first amount of heat and being in thermal contactwith the heat pipe; and a cooling module including a heat sink inthermal contact with the heat pipe, the cooling module generating asecond amount of heat in a range from the first amount of heat to noheat; and wherein heat from the pluggable optical module is transferablethrough the heat pipe to the cooling module for dispersal from the heatsink.
 2. The apparatus of claim 1, wherein the pluggable optical moduleand the cooling module are removably engaged with the linecard.
 3. Theapparatus of claim 1, wherein the heat pipe is a first heat pipe,wherein the heat relay apparatus further comprises: a first heat relayreceiver assembly comprising a first receiver housing having a slot andin thermal contact with the first heat pipe; and a second heat relayreceiver assembly comprising a second receiver housing having a slot andin thermal contact with the first heat pipe; and wherein the apparatusfurther comprises: a second heat pipe having a pluggable optical moduleportion contacting the pluggable optical module and a plug portionremovably positioned within the slot of, and in thermal contact with,the first receiver housing; and a third heat pipe having a heat sinkportion in thermal contact with the heat sink of the cooling module anda plug portion removably positioned within the slot of, and in thermalcontact with, the second receiver housing; and wherein heat from thepluggable optical module is transferable through the second heat pipe,the first heat pipe, and the third heat pipe to the cooling module fordispersal from the heat sink.
 4. The apparatus of claim 3, wherein thesecond heat pipe is removable from the first receiver housing while thelinecard is receiving electrical power.
 5. The apparatus of claim 3,wherein the third heat pipe is removable from the second receiverhousing while the linecard is receiving electrical power.
 6. Theapparatus of claim 3, wherein the heat sink is a first heat sink, theapparatus further comprising a second heat sink connected to thepluggable optical module and wherein the second heat pipe is in thermalcontact with the second heat sink.
 7. The apparatus of claim 3, whereinthe heat relay apparatus further comprises a first contact slug inbetween and in thermal contact with the first receiver housing and thefirst heat pipe; and a second contact slug in between and in thermalcontact with the second receiver housing and the first heat pipe.
 8. Theapparatus of claim 7, wherein the first heat relay receiver assemblyfurther comprises: a first clip located inside the slot of the firstreceiver housing, and in thermal contact with the first contact slug; afirst leaf spring extending into the slot of the first receiver housing;and wherein the second heat relay receiver assembly further comprises: asecond clip located inside the slot of the second receiver housing, andin thermal contact with the second contact slug; and a second leafspring extending into the slot of the second receiver housing.
 9. Theapparatus of claim 8, wherein the first heat relay receiver assemblyfurther comprises a first compressible thermal gap filler between thesecond heat pipe and the first clip, and wherein the second heat relayreceiver assembly further comprises a second compressible thermal gapfiller between the third heat pipe and the second clip.
 10. A method forcooling a telecommunication module, comprising: positioning atelecommunication chassis having a heat relay network system in anairflow, the heat relay network system comprising: a linecard comprisinga circuit board having a front side connectable to a pluggable opticalmodule and a back side opposite the front side; a heat relay apparatuscomprising a heat pipe on the circuit board; the pluggable opticalmodule generating a first amount of heat and being in thermal contactwith the heat pipe; and a cooling module including a heat sink inthermal contact with the heat pipe, the cooling module generating asecond amount of heat in a range from the first amount of heat to noheat; transferring heat from the pluggable optical module through theheat pipe to the heat sink of the cooling module; and dispersing heatfrom the heat sink of the cooling module to the airflow.
 11. The methodfor cooling a telecommunication module of claim 10, wherein thepluggable optical module and the cooling module are removably engagedwith the linecard.
 12. The method for cooling a telecommunication moduleof claim 10, wherein the heat pipe is a first heat pipe; wherein theheat relay apparatus further comprises: a first heat relay receiverassembly comprising a first receiver housing having a slot and inthermal contact with the first heat pipe; and a second heat relayreceiver assembly comprising a second receiver housing having a slot andin thermal contact with the first heat pipe; and wherein the heat relaynetwork system further comprises: a second heat pipe having a pluggableoptical module portion contacting the pluggable optical module and aplug portion removably positioned within the slot of, and in thermalcontact with, the first receiver housing; and a third heat pipe having aheat sink portion in thermal contact with the heat sink of the coolingmodule and a plug portion removably positioned within the slot of, andin thermal contact with, the second receiver housing; and wherein heatfrom the pluggable optical module is transferable through the secondheat pipe, the first heat pipe, and the third heat pipe to the coolingmodule for dispersal from the heat sink to the airflow.
 13. The methodfor cooling a telecommunication module of claim 12, wherein the secondheat pipe is removable from the first receiver housing while thelinecard is receiving electrical power.
 14. The method for cooling atelecommunication module of claim 12, wherein the third heat pipe isremovable from the second receiver housing while the linecard isreceiving electrical power.
 15. The method for cooling atelecommunication module of claim 12, wherein the heat sink of thecooling module is a first heat sink, wherein the heat relay networksystem comprises a second heat sink connected to the pluggable opticalmodule, and wherein the second heat pipe is in thermal contact with thesecond heat sink.
 16. The method for cooling a telecommunication moduleof claim 12, wherein the heat relay apparatus further comprises a firstcontact slug in between and in thermal contact with the first receiverhousing and the first heat pipe; and a second contact slug in betweenand in thermal contact with the second receiver housing and the firstheat pipe.
 17. The method for cooling a telecommunication module ofclaim 16, wherein the first heat relay receiver assembly furthercomprises: a first clip located inside the slot of the first receiverhousing, and in thermal contact with the first contact slug; a firstleaf spring extending into the slot of the first receiver housing; andwherein the second heat relay receiver assembly further comprises: asecond clip located inside the slot of the second receiver housing, andin thermal contact with the second contact slug; and a second leafspring extending into the slot of the second receiver housing.